/*

   Copyright 2001  The Apache Software Foundation 

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.

 */
package org.apache.batik.ext.awt.image.renderable;

import java.awt.geom.Rectangle2D;

import org.apache.batik.ext.awt.image.Light;

/**
 * This filter primitive lights an image using the alpha channel as a bump map. 
 * The resulting image is an RGBA opaque image based on the light color
 * with alpha = 1.0 everywhere. The lighting calculation follows the standard diffuse
 * component of the Phong lighting model. The resulting image depends on the light color, 
 * light position and surface geometry of the input bump map.
 *
 * This filter follows the specification of the feDiffuseLighting filter in 
 * the SVG 1.0 specification.
 *
 * @author <a href="mailto:vincent.hardy@eng.sun.com">Vincent Hardy</a>
 * @version $Id$
 */
public interface DiffuseLightingRable extends FilterColorInterpolation {
    /**
     * Returns the source to be filtered
     */
    public Filter getSource();

    /**
     * Sets the source to be filtered
     */
    public void setSource(Filter src);

    /**
     * @return Light object used for the diffuse lighting
     */
    public Light getLight();

    /**
     * @param light New Light object
     */
    public void setLight(Light light);

    /**
     * @return surfaceScale
     */
    public double getSurfaceScale();

    /**
     * Sets the surface scale
     */
    public void setSurfaceScale(double surfaceScale);

    /**
     * @return diffuse constant, or kd.
     */
    public double getKd();

    /**
     * Sets the diffuse constant, or kd
     */
    public void setKd(double kd);

    /**
     * @return the litRegion for this filter
     */
    public Rectangle2D getLitRegion();

    /**
     * Sets the litRegion for this filter
     */
    public void setLitRegion(Rectangle2D litRegion);

    /**
     * Returns the min [dx,dy] distance in user space for evalutation of 
     * the sobel gradient.
     */
    public double [] getKernelUnitLength();

    /**
     * Sets the min [dx,dy] distance in user space for evaluation of the 
     * sobel gradient. If set to zero or null then device space will be used.
     */
    public void setKernelUnitLength(double [] kernelUnitLength);
}

